What some people see as a cop-out for bad decision-making, others see as a legitimate disorder worthy of official classification

People cheat. They juggle multiple lovers. They have serial relationships. They watch porn.

You could chalk it up to the spectrum of sexual appetites, destructive as some may be. Or you could check yourself into rehab for sexual addiction.

That's how it went for Terrie, a then-married Arkansas schoolteacher with three kids. What began as giddy email flirtations with her former teacher turned into an affair, and when that ended, she had another affair, and then another, with men she met online.

Over six years, Terrie says she had yearlong affairs with six men, often securing the next before letting go of the one before.

"I was just possessed, I guess, with this drive to keep having that giddy vibe," said Terrie, now 46 and living in Memphis, Tenn., who asked that her last name not be published.

Terrie is among a growing number of Americans seeking treatment for sex addiction, an unofficial diagnosis that nonetheless gets bandied about every time celebrities or politicians are caught with their pants down. The number of sex addiction therapists certified by the International Institute for Trauma & Addiction Professionals worldwide has risen from about 400 to 1,100 in the past five years, said IITAP Vice President Tami VerHelst.

Sex addiction refers to an inability to stop sexual behavior even as it damages one's life. Terrie says that even when her life crumbled — she got involved with an 18-year-old student (it didn't get physical until after he graduated), her husband found out, she quit her job, she tried to kill herself by crashing her car into a tree — she continued sneaking around, miserable about leading a double life but "unable to not do it."

As the American Psychiatric Association prepares to publish the fifth edition of the Diagnostic and Statistical Manual, its standard for classifying mental illnesses, debate flares anew about whether compulsive sexual behavior is a disorder in itself, a symptom of other psychological problems or merely the fruit of poor decision-making.

A proposed mental condition termed "hypersexual disorder" is being considered for inclusion in the appendix of the DSM-V, due for publication in May 2013. Its placement in the appendix would indicate hypersexual disorder is a phenomenon worthy of scientific interest but in need of more research before being considered an official diagnosis.

"I think (in the appendix) is where it belongs because we do need more study," said clinical psychologist Rory Reid, the independent principle investigator of the field trial to test the proposed diagnostic criteria. Reid opposes the term "addiction," which he says is overused for anything pleasurable, and believes the label lacks empirical evidence from neuroimaging, genetics, or studies assessing patterns of tolerance or withdrawal.

Currently, the DSM-IV has an entry for "sexual disorder not otherwise specified," defined as distress about repeated sexual relationships with a succession of lovers who exist "as things to be used," a description Reid says is vague and limited.

To meet the proposed criteria for hypersexual disorder, an adult would have to meet four of the following five criteria, repeatedly, over a period of at least six months: spend excessive time engaged in sexual fantasies, urges and behaviors; use sex in response to unpleasant moods like anxiety, depression or boredom; use sex in response to stressful life events; unsuccessfully try to control or reduce sexual activities; and pursue sex despite risks for physical or emotional harm. The behavior also must cause personal distress or impairment in a person's social or work life.

A field trial to test the criteria, in which two different clinicians evaluated each of 207 patients who sought treatment (94 percent of them men), found that hypersexual disorder could be reliably diagnosed, said Reid, a research psychologist at the Neuropsychiatric Institute at the University of California at Los Angeles.

"These aren't just people who are sexually promiscuous, these are guys who feel a compulsion," he said. They might spend three hours a day masturbating to pornography that they'd rather spend exercising or hanging out with their family, or put themselves at risk by going to a dodgy part of town to have sex with a prostitute, Reid said.

Among women who seek treatment for sexual behavior, the compulsion often isn't so much about sex as about love and relationships, said Alisha Shelbourn, an addiction therapist at Life Healing Center in Santa Fe, N.M. These people might have one relationship after another, fall in love before the first date, have multiple relationships simultaneously in order to feel secure, or spend hours fantasizing about being rescued.

That might ring true for a lot of people, but it crosses the line of normalcy when it becomes all-consuming and negatively impacts other aspects of life.

"Where it becomes abnormal is when it impacts self-esteem, finances, starts to get into eating disorders, or spending money on cosmetic surgery to get the perfect partner," Shelbourn said. "It becomes an obsession, takes over their lives." She said clients do experience withdrawal; Terrie said she felt "constant anxiety and a feeling of doom" when she wasn't distracting herself with her romances. Performing in recovery theater, she said, now fills the void.

Mary Deitch, director of the Keystone Center Extended Care Unit in Chester, Pa., a residential center specializing in sexual compulsivity and trauma, said that while the causes of sexual compulsivity are not fully understood, her clinical impressions are that it stems from people not getting their needs met during childhood, perhaps due to trauma, a chaotic household or emotional neglect. They self-soothe using easily accessible behaviors, often starting with masturbation, when they don't know how else to cope with uncomfortable emotions such as anger, frustration, fear or stress.

A cycle of self-soothing, feeling shame, then self-soothing again, often drives the compulsion, Deitch said. The therapy aims to teach people they do have emotional tolerance and offers them other coping skills, such as using emotional language, mindfulness or art therapy.

Critics raise numerous concerns about making pathologies of sexual behaviors. First of all, what's so bad about using sex to handle stress or anxiety?

"It's a moral judgment based on cultural biases," said David Ley, a clinical psychologist based in Albuquerque, N.M., and author of "The Myth of Sex Addiction" (Rowman and Littlefield), which was published in March.

The distress component also is subjective, Ley said. Someone very religious might be distraught that they're masturbating once a week, but does that make them hypersexual? And are serial cheaters distressed because of their behavior, or because they were caught?

That's not to say people don't engage in self-destructive sexual behaviors or have trouble controlling their thoughts or urges, Ley said, but he believes those are symptoms of other psychological or relationship issues rather than an independent disorder.

Blaming bad sexual choices on a disease is dangerous, he said, because it excuses people from exercising personal responsibility over their actions.

Sexual addiction treatment centers, of course, disagree.

"It's actually the opposite of an excuse," Deitch said. "We're asking people to think about their motives and change how they interact with the world."

Keystone clients undergo group therapy daily for a minimum of 30 days ($14,970) to explore why they are acting out sexually and to own up to the harm they might have caused others. When they leave, they're urged to attend 12-step programs like Sex Addicts Anonymous, where total sexual abstinence is not the goal. Rather, participants try to establish a healthy sexuality (which means something different for everyone).

Ley said treatment centers are "trying to sell snake oil," with no empirical evidence proving their programs' effectiveness. But, he said, he supports putting hypersexual disorder in the appendix of the DSM "so we can try and identify if there's any kernel of truth here."